Space and Astronomy in general

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This is a thread to put such things in general.

The interstellar neighborhood, in 3D

Beware of the leopard.

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Because 3D is awesome when it isn't movies.

What you're looking at and source: http://earthsky.org/space/animated-gifs-of-deep-space-objects-in-3d

Tanglebones wrote:

youtube

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I really like that image; unfortunately it's just wrong in any meaningful sense. Sidereally the solar system is moving laterally, (in the plane of the solar system). So it would be sliding sideways, not going up or down. There wouldn't be a spiral. It would resemble a cycloid, save that given relative velocities of all involved, it wouldn't look like anything.

http://en.wikipedia.org/wiki/Milky_Way has a lot of concise information, but to condense, the Sun is moving about 200km/sec in it's galactic orbit. If you think of the solar system as being flat, it's moving almost perfectly sideways. By comparison, the earth is orbiting the sun at ~30 km/sec, so it's basically standing still. Mercury(the fastest) goes about half again that fast, so the motion would be so tiny as to be unnoticeable. This is to say nothing of the absolute difference in size of orbits, which would also diminish things to invisibility on any to-scale large reference.

The galaxy is moving ~600km/sec compared to nearby galaxies depending on how you measure things. The problem with that is it's also moving in totally different directions depending on how you measure things.

I remember taking astronomy for my undergrad degree and freaking out when I realized that not only in is the galaxy we reside in spinning around an axis, the galaxy as an entirety is moving through space. That blew my mind.

I don't spend a lot of time thinking about space and the universe, it reminds me of how small we are and how we are so insignificant. It does help to keep life in perspective though.

Of course, this may all be the vodka talking.

Tim

http://exoplanet.eu/ Sometimes called the Exoplanet Excyclopedia, this has most of the relevant information about exoplanets we know. The site isn't very stable. A confirmed planet is one that has been detected by an independent study or implement. There are 861 confirmed planets in 677 systems as of this post. These things are everywhere.

What I do is select all criteria and start looking for cool stuff. 55 Cancer e is about eight times the mass of the Earth. It may be made almost entirely of carbon. It's orbiting a neutron star. What does that mean? It's mostly diamond, and mostly is on the order of three Earth masses.

http://en.spaceengine.org/ Is apparently hosting a game where you look at cool stuff. I haven't gotten it to work on my machine yet. I found the site when their thread http://en.spaceengine.org/forum/22-1148-1 seemed to aggregate exoplanet news.

Yonder wrote:

asteroids

That was very cool. And we're still discovering them by the thousands with these automated systems. Crazy.

(via NPR)

CSA Astronaut Chris Hadfield performed a simple science experiment designed by grade 10 Lockview High School students Kendra Lemke and Meredith Faulkner. The students from Fall River, Nova Scotia won a national science contest held by the Canadian Space Agency with their experiment on surface tension in space using a wet washcloth. Credit: Canadian Space Agency/NASA

(more info)

Coool washcloth!

Three years of the sun in three minutes:

(via NPR)

Times of note:

NASA wrote:

"There are several noteworthy events that appear briefly in this video. They include the two partial eclipses of the sun by the moon, two roll maneuvers [by the observatory, as it changes position], the largest flare of this solar cycle, comet Lovejoy, and the transit of Venus. The specific time for each event is listed below, but a sharp-eyed observer may see some while the video is playing.
— "00:30;24 Partial eclipse by the moon
— "00:31;16 Roll maneuver
— "01:11;02 August 9, 2011 X6.9 Flare, currently the largest of this solar cycle
— "01:28;07 Comet Lovejoy, December 15, 2011
— "01:42;29 Roll Maneuver
— "01:51;07 Transit of Venus, June 5, 2012
— "02:28;13 Partial eclipse by the moon"

Katy wrote:

Washcloth video

I find it interesting that it's apparently no problem having that water floating all over the place. Looks like an awful lot of equipment and exposed wiring and other stuff in that room.

That surprised me too, but if you look in the background, there's another astronaut sponging up stray droplets with another washcloth. And most of the water (yay, surface tension!) stays pretty close to the demonstrator.

Fairly concise paper on the variability of c. This isn't a new thing. Still, this paper does seem to break it down without as much nonsense attached as normally gets bolted on when this matter gets discussed. The counter point is the second to last paragraph from the end.

Some scientists are a bit skeptical, though. Jay Wacker, a particle physicist at the SLAC National Accelerator Laboratory, said he wasn't confident about the mathematical techniques used, and that it seemed in both cases the scientists weren't applying the mathematical tools in the way that most would. "The proper way to do this is with the Feynman diagrams," Wacker said. "It's a very interesting question [the speed of light]," he added, but the methods used in these papers are probably not sufficient to investigate it.

Unrelated, there's going to be a lunar launch from Wallops Island, Virginia in August.

Where Have We Been In Space

Reasonably complete. Doesn't include missions that never left terrestrial orbit.

PBS[/url]]When a massive power outage struck southern California in the 1990s, Los Angeles residents reportedly called 911 to express alarm about strange clouds hovering overhead; they were seeing the Milky Way for the first time.

Yeah if you've never seen dark sky it is certainly a worthwhile experience.

Unfortunately it's an increasingly difficult task to have that experience, unless you happen to live near a dark sky preserve,
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Ordered this earlier today. It's supposed to arrive on Saturday, and I'm really looking forward to taking it out. The peak view of Saturn was the 28th, but it should still look really nice for a couple weeks.

That looks like a good rig Yonder, hell of a discount too if you managed to get that.

question:
Do we have any professional astronomers, astrophysicists, or cosmologists here at GWJ?

None of them seem like very populated or in demand career fields so probably not but figured I'd ask.

Miashara wrote:

Where Have We Been In Space

Reasonably complete. Doesn't include missions that never left terrestrial orbit.

Nice.

krev82 wrote:

That looks like a good rig Yonder, hell of a discount too if you managed to get that.

question:
Do we have any professional astronomers, astrophysicists, or cosmologists here at GWJ?

None of them seem like very populated or in demand career fields so probably not but figured I'd ask.

I know right! I couldn't believe I managed to snag that for $240.

Edit: Oh, and we have like 3 or 4 aerospace engineers (including me) but I don't know if we have people who are astronomers and astrophysicists.

Yonder wrote:

Ordered this earlier today. It's supposed to arrive on Saturday, and I'm really looking forward to taking it out. The peak view of Saturn was the 28th, but it should still look really nice for a couple weeks.

Just got back from our first outing. Other than a couple stars we looked at while searching for Saturn, today was all about Saturn. We definitely need some practice aiming the scope, and just experience in general. There were a couple false positives as we saw especially bright (in comparison to their immediate neighbors) stars, but once we got to Saturn it was absolutely unmistakable. Even at our lowest magnification (31x) the shape of the rings around Saturn was visible. At 80x it was starting to look absolutely gorgeous, and above that even the gap between Saturn and the rings was clear.

The highest magnification we got it under was 167x, although it wasn't that much better than the 80x, probably because our focusing skills were lacking along with everything else. We tried to get it from 167x to our effective max of 250x a few times, but lost it each time. It was getting late and cold, and we were quite happy with what we'd seen already, so we packed it up.

Next time we'll bring our motor mount along, and when we don't have to worry about us rotating out from under him we'll hopefully be able to get up to the 250x without losing him.

Ooh. Thread.

We're doing some neat stuff at the moment: http://www.bis.gov.uk/ukspaceagency

Hehe, it's good to live in Southern Nova Scotia. I can see Andromeda with my naked eye in my back yard. The Milky Way is bright enough to create faint shadows on a dark midsummer night. My situation was one of the big reasons I got a telescope. If I lived on Hawaii I'd have to try surfing too

There is a chance that GJ 1214b is a waterworld. It's about 2.7 times the radius of Earth, and probably less than one Earth's radius of that is the rocky core. So you're looking at an ocean covering the planet about 10,000 km deep. It's 2 million km from Gliese (GJ) with an orbital period of 38 hours. It may, may be tidally locked: ie one side always faces the sun. This would result in a tidal bulge going around the planet every day, with a mirroring bulge on the other side. The tidal bulge is 87 km high.

Edit: This is a modelling rabbit hole. It's getting weird.

It really wouldn't be a wall, it would be a smooth and steady transition invisible at the small scale.

Not only that, but because the distortion is caused by gravity, the entire distortion would be gravitationally flat. Meaning that if you had this shape perfectly smooth, and had a perfect marble on it, the marble wouldn't roll, because there wouldn't even be an imperceptibly small gradient as far as gravity is concerned. While if you put down a perfectly flat bar on the surface and looked super super closely it wouldn't match the surface.

Similar to how our equator is fatter than our pole.

The temperature gradient would be immense. Not only is atmospheric filtration less on the peak, but it would be in perpetual sunlight. Hurricane/monsoon's would be spitting off the backside of the peak almost constantly.

Possibly. I need to do more math on this.

Yonder wrote:

It really wouldn't be a wall, it would be a smooth and steady transition invisible at the small scale.

Not only that, but because the distortion is caused by gravity, the entire distortion would be gravitationally flat. Meaning that if you had this shape perfectly smooth, and had a perfect marble on it, the marble wouldn't roll, because there wouldn't even be an imperceptibly small gradient as far as gravity is concerned. While if you put down a perfectly flat bar on the surface and looked super super closely it wouldn't match the surface.

Similar to how our equator is fatter than our pole.

That was my initial correction, until I started including the Coriolis force. It doesn't wind (excuse me) up nearly that simple. The flatness isn't nearly that significant because angular movement is 5/3 Earth's. Also of interesting note is that the bulge is roughly 37% the scale height. You run into a mild air temperature gradient, similar to the difference between Florida and the top of the Appalachians.

Also we're neglecting the Coriolis force on the water of effectively infinite depth (compared to bulge height) which is not correct. You can't arbitrarily assume it's going to be flat because without continental resistance, you will have a standing wave with nodes at the halfway point between perihelion/antihelion and the terminators, and those nodes are going to be moving fast. Not relative to the planet, but fast enough for significant spin corrections.

The Sun just released it's largest set of flares for the year. Three of them. In a row.

http://www.nasa.gov/mission_pages/su...

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